A while ago my hard drive crashed. Because I couldn't afford a new one I decided to try and boot my laptop from an external hard drive while I save up for a new internal. I've been searching for how to do this and everyone is saying something different. I have my Windows OS disk (8) and an 80GB external drive. If I want to make the external drive bootable and use my laptop from it, how would I do it? Thanks.
Additional info: My laptop is an inspiron 5520, I am able to find the EHD in my boot settings and select it but I get a screen saying it's currently not bootable.